chore(core/rust): Try to simplify pagination a bit

[no changelog]

core/embed/rust/src/ui/component/mod.rs

@@ -13,7 +13,7 @@ pub use base::{Child, Component, ComponentExt, Event, EventCtx, Never, TimerToke
 pub use empty::Empty;
 pub use label::{Label, LabelStyle};
 pub use pad::Pad;
-pub use paginated::{Paginate, Paginated, PaginatedMsg};
+pub use paginated::{PageMsg, Paginate};
 pub use text::{
     formatted::FormattedText,
     layout::{LineBreaking, PageBreaking, TextLayout},

core/embed/rust/src/ui/component/paginated.rs

@@ -1,113 +1,18 @@
-use crate::ui::{
-    component::{
-        text::layout::{LayoutFit, TextNoOp},
-        Component, ComponentExt, Event, EventCtx, FormattedText, Pad,
-    },
-    display::Color,
-    geometry::Rect,
+use crate::ui::component::{
+    text::layout::{LayoutFit, TextNoOp},
+    FormattedText,
 };
 
-/// Implementations of `Page` wrap the component being paged. They also contain
-/// model-dependent logic like:
-///
-/// * rendering scrollbar
-/// * detecting swipe on TT
-/// * buttons for changing pages on T1
-/// * fading backlight
-pub trait Page {
-    type Content;
-    fn new(area: Rect, page: Self::Content, page_count: usize, active_page: usize) -> Self;
-    fn inner_mut(&mut self) -> &mut Self::Content;
-    fn page_count(&self) -> usize;
-    fn active_page(&self) -> usize;
-    fn fade_after_next_paint(&mut self);
-    fn content_area(area: Rect) -> Rect;
-}
-
-/// Implementation of `Page` is a `Component` returning this message.
+/// Common message type for pagination components.
 pub enum PageMsg<T, U> {
     /// Pass-through from paged component.
     Content(T),
 
-    /// Pass-through from other `Component`s.
-    Controls(U),
-
-    /// Page change requested.
-    ChangePage(usize),
-}
-
-/// Handles page redraw on `ChangePage` message, and other model-agnostic logic.
-pub struct Paginated<P> {
-    page: P,
-    pad: Pad,
-}
-
-pub enum PaginatedMsg<T, U> {
-    /// Pass-through from the paged `Component`.
-    Content(T),
-
     /// Messages from page controls outside the paged component. Currently only
     /// used on T1 for "OK" and "Cancel" buttons.
     Controls(U),
 }
 
-impl<P> Paginated<P>
-where
-    P: Page,
-    P::Content: Paginate,
-{
-    pub fn new(area: Rect, content: impl FnOnce(Rect) -> P::Content, background: Color) -> Self {
-        let active_page = 0;
-        let mut content = content(P::content_area(area));
-        let page_count = content.page_count();
-        Self {
-            page: P::new(area, content, page_count, active_page),
-            pad: Pad::with_background(area, background),
-        }
-    }
-}
-
-// C is type of message returned by page controls.
-impl<P, C> Component for Paginated<P>
-where
-    P: Page,
-    P: Component<Msg = PageMsg<<<P as Page>::Content as Component>::Msg, C>>,
-    P::Content: Paginate,
-    P::Content: Component,
-{
-    type Msg = PaginatedMsg<<<P as Page>::Content as Component>::Msg, C>;
-
-    fn event(&mut self, ctx: &mut EventCtx, event: Event) -> Option<Self::Msg> {
-        self.page.event(ctx, event).and_then(|msg| match msg {
-            PageMsg::Content(c) => Some(PaginatedMsg::Content(c)),
-            PageMsg::Controls(c) => Some(PaginatedMsg::Controls(c)),
-            PageMsg::ChangePage(page) => {
-                self.page.fade_after_next_paint();
-                self.page.inner_mut().change_page(page);
-                self.page.inner_mut().request_complete_repaint(ctx);
-                self.pad.clear();
-                None
-            }
-        })
-    }
-
-    fn paint(&mut self) {
-        self.pad.paint();
-        self.page.paint();
-    }
-}
-
-#[cfg(feature = "ui_debug")]
-impl<P> crate::trace::Trace for Paginated<P>
-where
-    P: Page + crate::trace::Trace,
-    P::Content: crate::trace::Trace,
-{
-    fn trace(&self, t: &mut dyn crate::trace::Tracer) {
-        self.page.trace(t);
-    }
-}
-
 pub trait Paginate {
     fn page_count(&mut self) -> usize;
     fn change_page(&mut self, active_page: usize);

core/embed/rust/src/ui/component/text/paragraphs.rs

@@ -38,7 +38,7 @@ where
     }
 
     pub fn add<D: DefaultTextTheme>(mut self, text_font: Font, content: T) -> Self {
-        if content.as_ref().len() == 0 {
+        if content.as_ref().is_empty() {
             return self;
         }
         let paragraph = Paragraph::new(

core/embed/rust/src/ui/model_t1/component/page.rs

@@ -1,39 +1,35 @@
 use crate::ui::{
-    component::{
-        paginated::{Page, PageMsg},
-        Component, Event, EventCtx, Never,
-    },
-    display,
+    component::{Component, ComponentExt, Event, EventCtx, Never, Pad, PageMsg, Paginate},
+    display::{self, Color},
     geometry::{Offset, Point, Rect},
 };
 
 use super::{theme, Button, ButtonMsg, ButtonPos};
 
 pub struct ButtonPage<T> {
+    content: T,
     scrollbar: ScrollBar,
+    pad: Pad,
     prev: Button<&'static str>,
     next: Button<&'static str>,
     cancel: Button<&'static str>,
     confirm: Button<&'static str>,
-    page: T,
 }
 
-impl<T> ButtonPage<T> {
-    fn areas(area: Rect) -> (Rect, Rect, Rect) {
-        let button_height = theme::FONT_BOLD.line_height() + 2;
-        let (content_area, button_area) = area.hsplit(-button_height);
-        let (content_area, scrollbar_area) = content_area.vsplit(-ScrollBar::WIDTH);
-        let (content_area, _) = content_area.hsplit(-1);
-        (content_area, scrollbar_area, button_area)
-    }
-}
+impl<T> ButtonPage<T>
+where
+    T: Paginate,
+    T: Component,
+{
+    pub fn new(area: Rect, content: impl FnOnce(Rect) -> T, background: Color) -> Self {
+        let (content_area, scrollbar_area, button_area) = Self::areas(area);
+        let mut content = content(content_area);
+        let pad = Pad::with_background(area, background);
 
-impl<T> Page for ButtonPage<T> {
-    type Content = T;
+        // Always start at the first page.
+        let scrollbar = ScrollBar::vertical_right(scrollbar_area, content.page_count(), 0);
 
-    fn new(area: Rect, page: T, page_count: usize, active_page: usize) -> Self {
-        let (_content_area, scrollbar_area, button_area) = Self::areas(area);
-        let scrollbar = ScrollBar::vertical_right(scrollbar_area, page_count, active_page);
+        // Create the button controls.
         let prev = Button::with_text(button_area, ButtonPos::Left, "BACK", theme::button_cancel());
         let next = Button::with_text(
             button_area,
@@ -53,36 +49,40 @@ impl<T> Page for ButtonPage<T> {
             "CONFIRM",
             theme::button_default(),
         );
+
         Self {
+            content,
             scrollbar,
+            pad,
             prev,
             next,
             cancel,
             confirm,
-            page,
         }
     }
 
-    fn inner_mut(&mut self) -> &mut T {
-        &mut self.page
-    }
-
-    fn page_count(&self) -> usize {
-        self.scrollbar.page_count
-    }
-
-    fn active_page(&self) -> usize {
-        self.scrollbar.active_page
+    fn areas(area: Rect) -> (Rect, Rect, Rect) {
+        let button_height = theme::FONT_BOLD.line_height() + 2;
+        let (content_area, button_area) = area.hsplit(-button_height);
+        let (content_area, scrollbar_area) = content_area.vsplit(-ScrollBar::WIDTH);
+        let (content_area, _) = content_area.hsplit(-1);
+        (content_area, scrollbar_area, button_area)
     }
 
-    fn fade_after_next_paint(&mut self) {}
-
-    fn content_area(area: Rect) -> Rect {
-        Self::areas(area).0
+    fn change_page(&mut self, ctx: &mut EventCtx, page: usize) {
+        // Change the page in the content, clear the background under it and make sure
+        // it gets completely repainted.
+        self.content.change_page(page);
+        self.content.request_complete_repaint(ctx);
+        self.pad.clear();
     }
 }
 
-impl<T: Component> Component for ButtonPage<T> {
+impl<T> Component for ButtonPage<T>
+where
+    T: Component,
+    T: Paginate,
+{
     type Msg = PageMsg<T::Msg, bool>;
 
     fn event(&mut self, ctx: &mut EventCtx, event: Event) -> Option<Self::Msg> {
@@ -90,34 +90,33 @@ impl<T: Component> Component for ButtonPage<T> {
             if let Some(ButtonMsg::Clicked) = self.prev.event(ctx, event) {
                 // Scroll up.
                 self.scrollbar.go_to_previous_page();
-                return Some(PageMsg::ChangePage(self.active_page()));
-            }
-        } else {
-            if let Some(ButtonMsg::Clicked) = self.cancel.event(ctx, event) {
-                return Some(PageMsg::Controls(false));
+                self.change_page(ctx, self.scrollbar.active_page);
+                return None;
             }
+        } else if let Some(ButtonMsg::Clicked) = self.cancel.event(ctx, event) {
+            return Some(PageMsg::Controls(false));
         }
 
         if self.scrollbar.has_next_page() {
             if let Some(ButtonMsg::Clicked) = self.next.event(ctx, event) {
                 // Scroll down.
                 self.scrollbar.go_to_next_page();
-                return Some(PageMsg::ChangePage(self.active_page()));
-            }
-        } else {
-            if let Some(ButtonMsg::Clicked) = self.confirm.event(ctx, event) {
-                return Some(PageMsg::Controls(true));
+                self.change_page(ctx, self.scrollbar.active_page);
+                return None;
             }
+        } else if let Some(ButtonMsg::Clicked) = self.confirm.event(ctx, event) {
+            return Some(PageMsg::Controls(true));
         }
 
-        if let Some(msg) = self.page.event(ctx, event) {
+        if let Some(msg) = self.content.event(ctx, event) {
             return Some(PageMsg::Content(msg));
         }
         None
     }
 
     fn paint(&mut self) {
-        self.page.paint();
+        self.pad.paint();
+        self.content.paint();
         self.scrollbar.paint();
         if self.scrollbar.has_previous_page() {
             self.prev.paint();
@@ -139,9 +138,9 @@ where
 {
     fn trace(&self, t: &mut dyn crate::trace::Tracer) {
         t.open("ButtonPage");
-        t.field("active_page", &self.active_page());
-        t.field("page_count", &self.page_count());
-        t.field("content", &self.page);
+        t.field("active_page", &self.scrollbar.active_page);
+        t.field("page_count", &self.scrollbar.page_count);
+        t.field("content", &self.content);
         t.close();
     }
 }

core/embed/rust/src/ui/model_t1/layout.rs

@@ -4,7 +4,7 @@ use crate::{
     error::Error,
     micropython::{buffer::Buffer, map::Map, obj::Obj, qstr::Qstr},
     ui::{
-        component::{text::paragraphs::Paragraphs, Child, FormattedText, Paginated, PaginatedMsg},
+        component::{text::paragraphs::Paragraphs, Child, FormattedText, PageMsg},
         display,
         layout::obj::LayoutObj,
     },
@@ -16,13 +16,13 @@ use super::{
     theme,
 };
 
-impl<T> TryFrom<PaginatedMsg<T, bool>> for Obj {
+impl<T> TryFrom<PageMsg<T, bool>> for Obj {
     type Error = Error;
 
-    fn try_from(val: PaginatedMsg<T, bool>) -> Result<Self, Self::Error> {
+    fn try_from(val: PageMsg<T, bool>) -> Result<Self, Self::Error> {
         match val {
-            PaginatedMsg::Content(_) => 2.try_into(),
-            PaginatedMsg::Controls(c) => Ok(c.into()),
+            PageMsg::Content(_) => 2.try_into(),
+            PageMsg::Controls(c) => Ok(c.into()),
         }
     }
 }
@@ -57,7 +57,7 @@ extern "C" fn ui_layout_new_confirm_action(
             .map(|label| |area, pos| Button::with_text(area, pos, label, theme::button_default()));
 
         let obj = LayoutObj::new(Child::new(Title::new(display::screen(), title, |area| {
-            Paginated::<ButtonPage<_>>::new(
+            ButtonPage::new(
                 area,
                 |area| {
                     FormattedText::new::<theme::T1DefaultText>(area, format)
@@ -85,7 +85,7 @@ extern "C" fn ui_layout_new_confirm_text(
             kwargs.get(Qstr::MP_QSTR_description)?.try_into_option()?;
 
         let obj = LayoutObj::new(Child::new(Title::new(display::screen(), title, |area| {
-            Paginated::<ButtonPage<_>>::new(
+            ButtonPage::new(
                 area,
                 |area| {
                     Paragraphs::new(area)

core/embed/rust/src/ui/model_tt/component/page.rs

@@ -1,65 +1,70 @@
 use crate::ui::{
-    component::{
-        paginated::{Page, PageMsg},
-        Component, Event, EventCtx, Never,
-    },
-    display,
+    component::{Component, ComponentExt, Event, EventCtx, Never, Pad, PageMsg, Paginate},
+    display::{self, Color},
     geometry::{Offset, Point, Rect},
 };
 
 use super::{theme, Swipe, SwipeDirection};
 
 pub struct SwipePage<T> {
+    content: T,
+    pad: Pad,
     swipe: Swipe,
     scrollbar: ScrollBar,
-    page: T,
     fade: Option<i32>,
 }
 
-impl<T> SwipePage<T> {
-    fn setup_swipe(scrollbar: &ScrollBar, swipe: &mut Swipe) {
-        swipe.allow_up = scrollbar.has_next_page();
-        swipe.allow_down = scrollbar.has_previous_page();
-    }
-}
+impl<T> SwipePage<T>
+where
+    T: Paginate,
+    T: Component,
+{
+    pub fn new(area: Rect, content: impl FnOnce(Rect) -> T, background: Color) -> Self {
+        // Content occupies the whole area.
+        let mut content = content(area);
 
-impl<T> Page for SwipePage<T> {
-    type Content = T;
+        // Always start at the first page.
+        let scrollbar = ScrollBar::vertical_right(area, content.page_count(), 0);
 
-    fn new(area: Rect, page: T, page_count: usize, active_page: usize) -> Self {
-        let scrollbar = ScrollBar::vertical_right(area, page_count, active_page);
-        let mut swipe = Swipe::new(area);
-        Self::setup_swipe(&scrollbar, &mut swipe);
+        let swipe = Self::make_swipe(area, &scrollbar);
+        let pad = Pad::with_background(area, background);
         Self {
-            swipe,
+            content,
             scrollbar,
-            page,
+            swipe,
+            pad,
             fade: None,
         }
     }
 
-    fn inner_mut(&mut self) -> &mut T {
-        &mut self.page
+    fn make_swipe(area: Rect, scrollbar: &ScrollBar) -> Swipe {
+        let mut swipe = Swipe::new(area);
+        swipe.allow_up = scrollbar.has_next_page();
+        swipe.allow_down = scrollbar.has_previous_page();
+        swipe
     }
 
-    fn page_count(&self) -> usize {
-        self.scrollbar.page_count
-    }
+    fn change_page(&mut self, ctx: &mut EventCtx, page: usize) {
+        // Adjust the swipe parameters.
+        self.swipe = Self::make_swipe(self.swipe.area, &self.scrollbar);
 
-    fn active_page(&self) -> usize {
-        self.scrollbar.active_page
-    }
+        // Change the page in the content, make sure it gets completely repainted and
+        // clear the background under it.
+        self.content.change_page(page);
+        self.content.request_complete_repaint(ctx);
+        self.pad.clear();
 
-    fn fade_after_next_paint(&mut self) {
+        // Swipe has dimmed the screen, so fade back to normal backlight after the next
+        // paint.
         self.fade = Some(theme::BACKLIGHT_NORMAL);
     }
-
-    fn content_area(area: Rect) -> Rect {
-        area
-    }
 }
 
-impl<T: Component> Component for SwipePage<T> {
+impl<T> Component for SwipePage<T>
+where
+    T: Paginate,
+    T: Component,
+{
     type Msg = PageMsg<T::Msg, Never>;
 
     fn event(&mut self, ctx: &mut EventCtx, event: Event) -> Option<Self::Msg> {
@@ -68,30 +73,32 @@ impl<T: Component> Component for SwipePage<T> {
                 SwipeDirection::Up => {
                     // Scroll down, if possible.
                     self.scrollbar.go_to_next_page();
-                    Self::setup_swipe(&self.scrollbar, &mut self.swipe);
-                    return Some(PageMsg::ChangePage(self.active_page()));
+                    self.change_page(ctx, self.scrollbar.active_page);
+                    return None;
                 }
                 SwipeDirection::Down => {
                     // Scroll up, if possible.
                     self.scrollbar.go_to_previous_page();
-                    Self::setup_swipe(&self.scrollbar, &mut self.swipe);
-                    return Some(PageMsg::ChangePage(self.active_page()));
+                    self.change_page(ctx, self.scrollbar.active_page);
+                    return None;
                 }
                 _ => {
                     // Ignore other directions.
                 }
             }
         }
-        if let Some(msg) = self.page.event(ctx, event) {
+        if let Some(msg) = self.content.event(ctx, event) {
             return Some(PageMsg::Content(msg));
         }
         None
     }
 
     fn paint(&mut self) {
-        self.page.paint();
+        self.pad.paint();
+        self.content.paint();
         self.scrollbar.paint();
         if let Some(val) = self.fade.take() {
+            // Note that this is blocking and takes some time.
             display::fade_backlight(val);
         }
     }
@@ -104,9 +111,9 @@ where
 {
     fn trace(&self, t: &mut dyn crate::trace::Tracer) {
         t.open("SwipePage");
-        t.field("active_page", &self.active_page());
-        t.field("page_count", &self.page_count());
-        t.field("content", &self.page);
+        t.field("active_page", &self.scrollbar.active_page);
+        t.field("page_count", &self.scrollbar.page_count);
+        t.field("content", &self.content);
         t.close();
     }
 }
@@ -138,11 +145,15 @@ impl ScrollBar {
     }
 
     pub fn go_to_next_page(&mut self) {
-        self.active_page = self.active_page.saturating_add(1).min(self.page_count - 1);
+        self.go_to(self.active_page.saturating_add(1).min(self.page_count - 1));
     }
 
     pub fn go_to_previous_page(&mut self) {
-        self.active_page = self.active_page.saturating_sub(1);
+        self.go_to(self.active_page.saturating_sub(1));
+    }
+
+    pub fn go_to(&mut self, active_page: usize) {
+        self.active_page = active_page;
     }
 }
 

core/embed/rust/src/ui/model_tt/component/swipe.rs

@@ -14,7 +14,7 @@ pub enum SwipeDirection {
 }
 
 pub struct Swipe {
-    area: Rect,
+    pub area: Rect,
     pub allow_up: bool,
     pub allow_down: bool,
     pub allow_left: bool,